Rainbow Trout as Surrogate Parents for King Salmon
Researchers have developed a method that allows rainbow trout to repeatedly act as surrogate parents for king salmon, a species that can only reproduce once in its lifetime. This breakthrough is expected to revolutionize salmon farming, contribute to healthy populations, and protect genetic diversity from climate change.
The key to this method lies in germline stem cells, which are responsible for producing eggs and sperm. While these cells remain active throughout the life of a rainbow trout, they disappear in king salmon after a single reproductive cycle. The research team successfully transplanted germline stem cells from king salmon into young rainbow trout that were unable to produce their own germ cells.
The results were remarkable. Five of the 24 female rainbow trout laid king salmon eggs annually for three years, and 10 of the 27 males produced king salmon sperm for four consecutive years. DNA analysis confirmed that the offspring were indeed king salmon. This method opens up the possibility of obtaining king salmon eggs and fry every year, significantly boosting breeding efficiency.
The researchers also demonstrated the potential of this technique for preserving endangered species. They transplanted germline stem cells from kokanee, another salmon species that reproduces only once, into rainbow trout, successfully producing kokanee eggs and sperm. This paves the way for using rainbow trout as surrogate parents to conserve and restore endangered salmon populations.
With king salmon facing extinction in some regions due to rising water temperatures, this research offers a glimmer of hope. The ability to breed king salmon more efficiently and preserve genetic diversity through surrogate parents could play a crucial role in ensuring the survival of this iconic species.